恶性肿瘤防治的关键在于“三早”，60年代开始的，在食管癌高发农村对30岁以上人群进行的食管吞网细胞学普查，已近40年。在普查发现的食管癌中，早期癌可占80％以上，而在郑州则不及2％。早期癌往往数年后方有临床症状，患者不可能主动就医。因而在医院就诊者多系中晚期病人， The key to the prevention and control of malignant tumors lies in the “three mornings”. Since the 1960s, it has been nearly 40 years since the esophageal swallowing network cytology survey conducted on people with high incidence of esophageal cancer in the rural areas over the age of 30 years. Among esophageal cancers discovered in the census, early cancers can account for more than 80%, while in Zhengzhou they are less than 2%. Early cancer often has clinical symptoms after several years, and patients are not likely to seek medical attention. Therefore, many patients attending hospitals are middle-late patients.